Pack-level and space-level liquid nitrogen fire suppression linkage system and method for energy storage power station

This patent application claims the benefit and priority of Chinese Patent Application No. 202411437849.5, filed with the China National Intellectual Property Administration on Oct. 15, 2024, the disclosure of which is incorporated by reference herein in its entirety as part of the present application.

The present disclosure belongs to the technical field of fire suppression for energy storage power stations, and particularly relates to a pack-level and space-level liquid nitrogen fire suppression linkage system and method for a centralized energy storage power station.

Lithium batteries have become a primary solution in China's electrochemical energy storage sector due to their advantages such as high energy density, high efficiency, and long service life. However, when subjected to external abuse conditions such as overheating, puncture, crush, overcharging, and overdischarging, lithium batteries can undergo thermal runaway, releasing a significant amount of heat and smoke, posing a high fire risk. This is particularly concerning in large-scale centralized energy storage power stations, where the high density of lithium batteries and highly concentrated energy make thermal runaway highly likely to trigger large-scale chain reactions, including fires or even explosions. Therefore, effective fire suppression technologies and methods are crucial to ensuring the safe operation of electrochemical energy storage power stations.

Currently, gaseous extinguishing agents such as perfluorohexanone and heptafluoropropane, as well as water-based extinguishing agents represented by fine water mist, are commonly used in lithium-ion battery energy storage power stations. However, their fire suppression effectiveness is limited, and none can meet the fire suppression requirements such as rapidly extinguishing open flames, providing sustained cooling, or suppressing explosions. Moreover, they fail to completely halt internal chemical reactions within the batteries, thereby being unable to effectively curb the progression and impact of battery fires.

To address the aforementioned technical limitations, an objective of the present disclosure is to provide a pack-level and space-level liquid nitrogen fire suppression linkage system and method for a centralized energy storage power station so as to enhance the fire suppression efficiency while ensuring reliability and cost-effectiveness.

In order to solve the above technical problems, the present disclosure adopts the following technical solutions.

A pack-level and space-level liquid nitrogen fire suppression linkage system for an energy storage power station includes an energy storage cabin,

According to the above technical solution, a fire suppression method using the pack-level and space-level liquid nitrogen fire suppression linkage system for an energy storage power station described above includes the following steps:

Further, a space-level fire suppression logic in step 1 is as follows:

Further, a pack-level fire suppression logic in step 1 is as follows:

The present disclosure has the following beneficial effects: the space-level and pacl-level liquid nitrogen fire suppression pipes in adjacent energy storage rooms or subareas are connected and controlled using the solenoid valves. Not only is the independence of the system in each subarea guaranteed, but also the safety redundancy of alternate linkage of used and standby liquid nitrogen explosion and fire suppression devices is realized, thereby improving the reliability of the liquid nitrogen explosion and fire suppression devices. With space-level and pack-level graded warning response mechanisms and fire suppression strategies, space-level liquid nitrogen explosion and fire suppression devices are used in sequence in combination with pack-level second-level warning pulsed liquid nitrogen spraying and third-level warning continuous liquid nitrogen spraying, thereby reducing false alarms and redundant responses and improving the resource utilization efficiency and the fire suppression efficacy. The fire suppression efficiency is enhanced while ensuring reliability and cost-effectiveness.

The technical solutions of the embodiments of the present disclosure are clearly and completely described below with reference to the accompanying drawings. Apparently, the described embodiments are merely a part rather than all of the embodiments of the present disclosure. All other embodiments obtained by a person of ordinary skill in the art on the basis of the embodiments of the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.

As shown inand, the present disclosure provides a technical solution, namely a pack-level and space-level liquid nitrogen fire suppression linkage system for an energy storage power station, including an energy storage cabin.

Inside the energy storage cabin, energy storage roomsin which battery clusters are stored are independent fire protection subareas. Two circular holes are formed on an upper side of a panel of a packof each battery cluster, with one circular hole for mounting a fire detectorand the other circular hole for laying a pack-level liquid nitrogen fire suppression branch pipe. An automatic quick opening valveis provided at a middle part of the pack-level liquid nitrogen fire suppression branch pipe, and a fire extinguishing nozzleis provided at a tail end of the pack-level liquid nitrogen fire suppression branch pipe.

A fire suppression cylinder roomis provided on each of two sides within the energy storage cabin, and a liquid nitrogen explosion and fire suppression deviceis provided in the fire suppression cylinder room. A high-pressure nitrogen cylinderis provided on one side and a liquid nitrogen tankis provided on another side within the liquid nitrogen explosion and fire suppression device. A gas inlet, a liquid outlet, and a liquid replenishing portare provided at a top of the liquid nitrogen tank. A gas outlet pipeis connected to a top of the high-pressure nitrogen cylinder, and one end of the gas outlet pipeis connected to a pressure relief valve. One end of the pressure relief valveis connected to a solenoid valve, and one end of the solenoid valveis connected to the gas inletat the top of the liquid nitrogen tank. The liquid nitrogen explosion and fire suppression device is driven by high-pressure nitrogen. The liquid outletat the top of the liquid nitrogen tankis connected to a liquid nitrogen fire suppression main pipeof a corresponding fire protection subarea. The liquid nitrogen fire suppression main pipecomes out of a top of the liquid nitrogen explosion and fire suppression deviceand has one end connected to a solenoid valve, and one end of the solenoid valveis connected to a diversion valvefor controlling a flow direction of a fire suppression medium liquid nitrogen. One end of the diversion valveis connected to a space-level liquid nitrogen fire suppression pipeand the other end of the diversion valve is connected to a pack-level liquid nitrogen fire suppression main pipe, and a plurality of fire extinguishing nozzlesare provided on the space-level liquid nitrogen fire suppression pipe.

The space-level liquid nitrogen fire suppression pipesand the pack-level liquid nitrogen fire suppression main pipesof the fire protection subareas are connected with solenoid valvesbeing provided at connections. When one liquid nitrogen explosion and fire suppression device fails or undergoes a pressure drop, linked control may be performed on the other liquid nitrogen explosion and fire suppression device to guarantee the reliability of the liquid nitrogen explosion and fire suppression device and enhance the fire suppression efficacy.

As shown in, a fire suppression method using the pack-level and space-level liquid nitrogen fire suppression linkage method includes the following steps.

In step 1, a fire alarm host receives alarm signals from detectors.

In step 2, the fire alarm host initiates linked activation of an audible and visual alarm and a fan in a corresponding subarea according to an actual alarm signal. High-pressure nitrogen of a high-pressure nitrogen cylinderenters a liquid nitrogen tankvia a gas inletthrough a pressure relief valveand a solenoid valve. Driven by the high-pressure nitrogen, liquid nitrogen enters a fire suppression main pipevia a liquid outlet.

In step 3, the fire suppression medium liquid nitrogen in the fire suppression main pipeenters a space-level liquid nitrogen fire suppression pipe, a pack-level liquid nitrogen fire suppression main pipe, and a pack-level liquid nitrogen fire suppression branch pipein the corresponding subarea via a solenoid valveand a diversion valve.

In step 4, a fire extinguishing nozzleof the space-level fire suppression pipe or a fire extinguishing nozzleof the pack-level liquid nitrogen fire suppression branch pipeis activated to spray liquid nitrogen for extinguishing fire.

In step 5, when the liquid nitrogen explosion and fire suppression devicein the corresponding subarea undergoes a host pressure drop or fails, the fire alarm host initiates linked activation of the other liquid nitrogen explosion and fire suppression device. The liquid nitrogen in the liquid nitrogen explosion and fire suppression deviceenters the space-level liquid nitrogen fire suppression pipe, the pack-level liquid nitrogen fire suppression main pipe, and the pack-level liquid nitrogen fire suppression branch pipeof the corresponding room on fire via the solenoid valvefor continuous fire extinguishing until the fire has been extinguished.

A space-level fire suppression logic in step 1 is as follows:

(1) When a control host detects a first-level warning signal from a detector, namely an abnormal battery temperature or generation of part of combustible gas, the control host initiates linked activation of an audible and visual alarm and an exhaust fan in a fire protection subarea and outputs an alarm signal to an external system, and the pack-level and space-level liquid nitrogen fire suppression linkage system is in a warning state.

(2) When the control host detects a second-level warning signal, the control host is in a delayed activation state. After a delay time expires, linked activation of the audible and visual alarm is initiated, the exhaust fan is turned off, and a subarea solenoid valve and a liquid nitrogen explosion and fire suppression device A corresponding to an energy storage room are activated for space fire suppression. The delay time may be set by a controller.

(3) When the control host detects that one detector is in a third-level alarm state and that at least two detectors are in a first-level or above alarm state, the pack-level and space-level liquid nitrogen fire suppression linkage system determines that a battery catches fire. At this time, the control host then initiates linked activation of the audible and visual alarm, turns off the exhaust fan, and activates the solenoid valve and the liquid nitrogen explosion and fire suppression device A corresponding to the energy storage room. Meanwhile, a liquid nitrogen explosion and fire suppression device B on the other side is switched to a ready working state, and when a liquid nitrogen pressure in the liquid nitrogen explosion and fire suppression device A drops to a certain value, the control host initiates linked activation of the solenoid valve and the liquid nitrogen explosion and fire suppression device B on the other side of the energy storage room to continue spraying liquid nitrogen for protecting the energy storage room.

A pack-level fire suppression logic in step 1 is as follows:

(1) When a pack-level detector is in a first-level warning state, the control host initiates linked activation of an audible and visual alarm system and the exhaust fan. At this time, the control host activates no liquid nitrogen explosion and fire suppression device for fire suppression.

(2) When the pack-level detector is in a second-level warning state, the control host initiates linked activation of the audible and visual alarm system, turns off the exhaust fan, and activates the liquid nitrogen explosion and fire suppression device for pulsed spraying.

(3) When the pack-level detector is in a third-level warning state, the control host initiates linked activation of the audible and visual alarm system, turns off the exhaust fan, and activates the liquid nitrogen explosion and fire suppression device for continuous spraying.

Apparently, those skilled in the art can make various changes and modifications to the present disclosure without departing from the spirit and scope of the present disclosure. Thus, provided that these alterations and modifications of the present disclosure fall within the scope of the claims of the present disclosure and their equivalents, the present disclosure is also intended to include these alterations and modifications.